least three deaths on the islands of St. Lucia, Martinique and Dominica on Friday.

The first hurricane of the Atlantic season, the Category 4 Dean was expected to gain power as it moves across the warm waters of the Caribbean through the weekend. The National Hurricane Center in Miami said its winds could surpass 155 mph as it approaches the Yucatan Peninsula and the Gulf of Mexico on Monday.

By Wednesday, there is a chance Dean could threaten the U.S., though it is expected to lose some of its punch as it travels over the Yucatan.

The immediate danger, however, comes Saturday as the storm passes south of Hispaniola, the island shared by the Dominican Republic and Haiti — both particularly prone to devastating floods.

The hurricane center issued a hurricane warning for the southern coast of the Dominican Republic early Saturday.

Haitian authorities issued an alert for coastal communities and ordered fishing boats to stay ashore until after the weekend. Prime Minister Portia Simpson-Miller of Jamaica — where a direct hit is expected Sunday — ordered shelters opened across the island and